386 COLLOIDS IN BIOLOGY AND MEDICINE 



In recent years we have become acquainted with a number of facts 

 which cannot be reconciled with the MEYER-OVERTON theory. For 

 instance, S. J. MELTZER showed that magnesium salts possess power- 

 ful narcotic properties. G. MANSFELD and BOSANYI then showed that 

 during profound magnesium narcosis there was absolutely no change 

 from the normal magnesium content of the brain. No increase in 

 Mg was demonstrable either in the lipoid or the lipoid free brain 

 substance. Furthermore, it developed, that the lipoid solubility of 

 the narcotics was to a certain extent merely accidental which paral- 

 leled other physico-chemical properties. According to J. TRAUBE 

 and J. CZAPEK diminution of surface tension parallels the narcotic 

 properties. We must emphasize, however, that in TRAUBE'S experi- 

 ments only the diminution of the surface tension to air was deter- 

 mined, whereas in the organism we are concerned with surface 

 tensions arising between two fluids or between a fluid and a gel 

 phase. The observations of BATTELLI and STERN have less connec- 

 tion with fat solubility; according to them there is a parallelism 

 between the precipitation of certain proteins, the inhibition of oxida- 

 tions in the tissues and the narcotizing activity of narcotics. WAR- 

 BURG and WIESEL showed that narcotics inhibit the ferment activity 

 of the pressed juice of yeast as well as of the yeast cells. Without 

 discussing the hypothetical basis of these processes we may conclude 

 from them that lipoid solubility does not constitute the sole physico- 

 chemical basis for narcosis. 



At present the tendency is to believe that the essential factor in 

 narcosis is a modification of the plasma pellicle which reversibly 

 changes its normal permeability for electrolytes, so that it is an open 

 question whether this membrane is pure protein (see p. 239 et seq., 

 membrane) or a mixture of lipoid and protein (see also S. LOEWE). 



An interesting support for this view was supplied by R. HOBER 

 and his pupil A. JOEL when they measured the electric conductivity 

 of blood corpuscles under the influence of narcotics. Although it is 

 true that blood corpuscles are not nerve cells there are such similari- 

 ties as justify us in applying to nerve cells, observations made on blood 

 corpuscles. R. HOBER found that narcotics inhibited the exit of 

 electrolytes when dilute, and increased it when concentrated. Nar- 

 cotics when dilute produce quite the opposite effect they do when 

 they are concentrated. This is analogous to the conductivity 

 determinations of OSTERHOUT on plant cells and the observations of 

 Sv. ARRHENIUS and BUBANOVIC as well as J. TRAUBE that small 

 amounts of many hemolytic agents inhibit homolysis. 



Obviously, every substance which dissolves in fat is not a narcotic; 

 it is such only if it can be again removed from the lipoid without 



